1.1. Field of the Invention
The present invention relates to networked computing, and in particular to a system and a method performed in a client-server computing environment for managing the access requested by users via an implementing application to a central, non-standard database type data repository having proprietary access and data structures, in which data repository the data integrity is controlled and checked by this application and, to which data repository other applications running independently of the data managing application must have access possibility.
1.2. Description and Disadvantages of Prior Art
The above-mentioned access method is used in prior art for example in a heterogeneous computing network, wherein the IBM z/OS or z/VM mainframe operating system manages a mainframe hardware, and wherein further hardware like IBM zSeries devices are configured, being installed next to different computers having a different operating system, like Linux, other Unix derivatives, or z/OS, OS/390, z/VM, VSE. With reference now to FIG. 1 which illustrates the structural components of a networked environment according to a prior art IBM mainframe environment, the present invention can be applied.
In this environment, in a concrete exemplary implementation in IBM mainframe technology a particular mainframe application denoted HCD (Hardware Configuration Definition) is occupied with the configuration of the hardware being implemented in this heterogeneous network. The HCD application runs on several user sessions on one or more hosts 10A, 10B, etc., and performs the logical configuration, as the hardware alone used in this heterogeneous network is not self-explanatory enough in order to describe a full and complete description of all aspects which must be defined in order to guarantee a proper operation of the hardware in the daily use. For example access rights defining particular systems and path information particular or other hardware being accessible by these systems are typical logical items of a logical configuration part which is subject to a fine-granular management by the HCD-application.
All those logical hardware definitions are saved in a centralised location in a particular file 22 denoted herein as IODF, which is an abbreviation for input/output definition file. This IODF 22 is a data repository which has proprietary access methods and data structures, which are not found in and which are not comparable to prior art database technology, like relational database technology.
With respect to the focus of the invention, in the course of the increasing trend to consolidate data centres, i.e., concentrate the functional operations of several data centers into a single, larger data center and thus to merge several of such I/O configuration repositories like above IODF, there is a growing need for accessing and changing the above-mentioned configuration data in a repository 22, in particular by multiple users.
So, different user groups require accessing the same I/O configuration data at the same time. Examples for those user groups are system programmers, hardware planner staff and cabling staff, etc. This repository 22 has a structure which gets referenced via its proprietary external interface (in this case the programs denoted “IOS”, “CP” and “ALLOCATION”), which can not be changed without major burden as to costs and staff. Further, it is always quite risky to change a running system by implementing major changes such as a replacement of the above-mentioned IODF 22 by a relational database, which is theoretically, of course possible, but which is not a reasonable alternative, as the number of concurrent users is relatively low, in most systems this is varying between two and six users. Thus, in prior art one decides to do a “pseudo multiple user access” as far as it can be managed by locking the IODF file 22 in case a different user has currently access to it and accepting a certain performance penalty due to this locking.
In the bottom left part of FIG. 1 and in the bottom right part thereof, respective personal computer systems 12 are depicted in order to illustrate that the above-mentioned staff members may have also access to above IODF 22 via such PCs and respective PC applications, denoted here as HCM (Hardware Configuration Manager).
As reveals from the drawing, when a HCM user wants to update the IODF, then he uses a host application 10C or 10 D denoted as HCD3 as a temporary server application. HCM itself is then acting as a client.
During such update of the centralised IODF 22 no other user—be that a different HCM user or another HCD user—may have access to the IODF 22, and not even for a read access.
In this particular environment the HCM application allows to configure even finer details of the hardware configuration, for example the cabling scheme used within the network. In order to manage these physical configuration data which is not shared by other users, a HCM user manages its own configuration file locally and as a separate physical file, in order to be able to perform local, physical updates in a stand-alone mode, first locally at the client's side. When performing a logical update with the centralized IODF 22, the corresponding physical updates are done to the local configuration file.
Such local updates are not made globally valid but reside in the local store of the client. A manual effort is required to provide these local updates to a different HCM client. Sharing of data defining the physical configuration is only possible by exchanging the appropriate HCM configuration file among HCM users, thereby forcing a timely serialisation of update accesses.
Having in mind the above-mentioned problems of merging data centres, a better way to provide a multiple user access to centralised, proprietary datastores 22 and 44 is strongly desired.
1.3. Objectives of the Invention
It is thus an objective of the present invention to provide an improved, cost-effective multiple-user access method in a networked client-server environment to a proprietary data repository not featuring database-type data structures and access methods.